Impact of carotid tortuosity on outcome after endovascular thrombectomy

Stent-retriever characteristics and strategies associated with recanalization in thrombectomy for acute ischemic stroke

INTRODUCTION

Predictive factors for successful reperfusion in mechanical thrombectomy for acute ischemic stroke, and especially technical factors, remain controversial. We investigated various techniques for better angiographic outcomes.

METHODS

In this retrospective study, acute ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy with combined technique were included. Scoring of the reperfusion grade for each attempt was conducted, and each attempt was divided into two groups based on successful reperfusion, which was defined using the presence or absence of modified thrombolysis in cerebral infarction 2b-3. The following characteristics were evaluated: the choice of stent-retriever, its length, occlusion site, thrombus position relative to deployed stent-retriever, methods of thrombectomy, and successful advancement of the distal access catheter to the proximal end of the thrombus.

RESULTS

Among 251 patients who underwent mechanical thrombectomy, 154 patients (255 attempts: mTICI 0-2a group, n = 119; mTICI 2b-3 group, n = 136) were included in the analysis. The thrombus position relative to the deployed stent-retriever was likely associated with successful reperfusion, although it was not statistically significant (proximal two-thirds 56.8 %; distal one-third 44.3 %, p = 0.09). Successful advancement of the distal access catheter was related to successful reperfusion both in univariate analysis (success 57.9 %; fail 35.8 %, p < 0.01) and in multivariate regression analysis (odds ratio 2.45; 95 % confidence interval: 1.30-4.61, p < 0.01).

CONCLUSIONS

Successful advancement of the distal access catheter to the proximal end of thrombus might be a key component for successful reperfusion in mechanical thrombectomy.

Tortuosity of middle cerebral artery M1 segment and outcomes after mechanical thrombectomy

BACKGROUND

We aimed to quantify the tortuosity of the middle cerebral artery (MCA) and assess its effects on radiological and clinical outcomes in patients with acute MCA occlusions who received mechanical thrombectomy (MT).

METHODS

This retrospective study enrolled 53 patients with acute ischemic stroke due to MCA M1 or M2 segment occlusion who underwent MT using stent retrievers (SRs). Tortuosity index (TI) was defined to quantify the tortuosity of the MCA M1 segment using the following formula: (actual distance / straight distance) × 100. For each patient, four TIs were measured in the anteroposterior and caudal views for both ipsilateral and contralateral sides to the occluded site (TI-APi, TI-APc, TI-CAUi, and TI-CAUc, respectively) using magnetic resonance angiography (MRA) or computed tomography angiography (CTA). We defined the first-pass effect (FPE) as first-pass mTICI classification ≥2b reperfusion.

RESULTS

Patients who did not achieve FPE had significantly higher TI-APi (112 vs. 106; P = 0.004), TI-APc (111 vs. 105; P = 0.005), TI-CAUi (110 vs. 105; P = 0.002), and TI-CAUc (110 vs. 105; P = 0.001) than those who achieved FPE. In multivariable analysis, higher TI-APi, TI-CAUi, and TI-APc were independently associated with an increased rate of unsuccessful FPE (odds ratio (OR) [95% confidence interval (CI)]: 1.25 [1.02-1.61], 1.21 [1.01-1.45], and 1.27 [1.03-1.73], respectively). TI-CAUi, TI-APc, and TI-CAUc were also independent predictors of the occurrence of intracranial hemorrhage after MT (OR [95% CI]: 1.15 [1.01-1.38], 1.14 [1.01-1.38], 1.25 [1.02-1.52], respectively).

CONCLUSIONS

The TIs of the MCA M1 segment on both ipsilateral and contralateral sides were associated with unfavourable outcomes after MT.

Sex differences in clot, vessel and tissue characteristics in patients with a large vessel occlusion treated with endovascular thrombectomy

INTRODUCTION

To improve our understanding of the relatively poor outcome after endovascular treatment (EVT) in women we assessed possible sex differences in baseline neuroimaging characteristics of acute ischemic stroke patients with large anterior vessel occlusion (LVO).

PATIENTS AND METHODS

We included all consecutive patients from the MR CLEAN Registry who underwent EVT between 2014 and 2017. On baseline non-contrast CT and CT angiography, we assessed clot location and clot burden score (CBS), vessel characteristics (presence of atherosclerosis, tortuosity, size, and collateral status), and tissue characteristics with the Alberta Stroke Program Early Computed Tomography Score (ASPECTS). Radiological outcome was assessed with the extended thrombolysis in cerebral infarction score (eTICI) and functional outcome with the modified Rankin Scale score (mRS) at 90 days. Sex-differences were assessed with multivariable regression analyses with adjustments for possible confounders.

RESULTS

3180 patients were included (median age 72 years, 48% women). Clots in women were less often located in the intracranial internal carotid artery (ICA) (25%vs 28%, odds ratio (OR) 0.85;95% confidence interval: 0.73-1.00). CBS was similar between sexes (median 6, IQR 4-8). Intracranial (aOR 0.73;95% CI:0.62-0.87) and extracranial (aOR 0.64;95% CI:0.43-0.95) atherosclerosis was less prevalent in women. Vessel tortuosity was more frequent in women in the cervical ICA (aOR 1.89;95% CI:1.39-2.57) and women more often had severe elongation of the aortic arch (aOR 1.38;95% CI:1.00-1.91). ICA radius was smaller in women (2.3vs 2.5 mm, mean difference 0.22;95% CI:0.09-0.35) while M1 radius was essentially equal (1.6vs 1.7 mm, mean difference 0.09;95% CI:-0.02-0.21). Women had better collateral status (⩾50% filling in 62%vs 53% in men, aOR 1.48;95% CI:1.29-1.70). Finally, ASPECT scores were equal between women and men (median 9 in both sexes, IQR 8-10vs 9-10). Reperfusion rates were similar between women and men (acOR 0.94;95% CI:0.83-1.07). However, women less often reached functional independence than men (34%vs 46%, aOR 0.68;95% CI:0.53-0.86).

DISCUSSION AND CONCLUSION

On baseline imaging of this Dutch Registry, men and women with LVO mainly differ in vessel characteristics such as atherosclerotic burden, extracranial vessel tortuosity, and collateral status. These sex differences do not result in different reperfusion rates and are, therefore, not likely to explain the worse functional outcome in women after EVT.

Carotid-cavernous fistula following mechanical thrombectomy of the tortuous internal carotid artery: A case report

BACKGROUND

A carotid-cavernous fistula (CCF) is an abnormal connection between the internal carotid artery (ICA) and the cavernous sinus. Although direct CCFs typically result from trauma or as an iatrogenic complication of neuroendovascular procedures, they can occur as surgery-related complications after mechanical thrombectomy (MT). With the widespread use of MT in patients with acute ischemic stroke complicated with large vessel occlusion, it is important to document CCF following MT and how to avoid them. In this study, we present a case of a patient who developed a CCF following MT and describe in detail the characteristics of ICA tortuosity in this case.

CASE SUMMARY

A 60-year-old woman experienced weakness in the left upper and lower limbs as well as difficulty speaking for 4 h. The neurological examination revealed left central facial paralysis and left hemiplegia, with a National Institutes of Health Stroke Scale score of 9. Head magnetic resonance imaging revealed an acute cerebral infarction in the right basal ganglia and radial crown. Magnetic resonance angiography demonstrated an occlusion of the right ICA and middle cerebral artery. Digital subtraction angiography demonstrated distal occlusion of the cervical segment of the right ICA. We performed suction combined with stent thrombectomy. Then, postoperative angiography was performed, which showed a right CCF. One month later, CCF embolization was performed, and the patient's clinical symptoms have significantly improved 5 mo after the operation.

CONCLUSION

Although a CCF is a rare complication after MT, it should be considered. Understanding the tortuosity of the internal carotid-cavernous sinus may help predict the complexity of MT and avoid this complication.

Balloon Gliding Technique: A novel use of balloon guiding catheters in accessing challenging circulations when treating acute ischemic stroke

BACKGROUND

Challenging arterial anatomy delays, or prevents timely endovascular treatment (EVT) of acute ischemic stroke (AIS). We introduce a new technique called 'Balloon Gliding Technique (BGT)' to overcome difficult arterial anatomy during EVT of AIS, utilizing flow-assistance to access challenging circulations.

METHODS

Retrospective review of a prospectively collected database of all patients presenting to a single institution with AIS who underwent EVT was performed from January 2021 to June 2021. Patients in whom BGT was performed were assessed. BGT consists of advancing the balloon guide catheter in the cervical carotid artery while its balloon is inflated, and therefore carried by downstream flow.

RESULTS

Of 51 patients presenting with AIS secondary to large vessel occlusion during the study period, five patients underwent BGT. All five patients had anterior circulation large vessel occlusions. Mean age of the BGT patients was 92.2 years, and all patients were females. A type 3 arch was present in all patients. BGT was performed in all cases following initial failure of conventional techniques to cannulate the target circulation. BGT was successful in achieving distal cervical carotid access in 4 out of the 5 patients in whom BGT was attempted. Successful recanalization (modified treatment in cerebral ischemia 2b-3) was obtained in all cases with no complications.

CONCLUSIONS

Balloon Gliding Technique (BGT) is a safe technique that can safely overcome challenging anatomy during endovascular treatment of acute ischemic stroke. Further studies can assist in demonstrating both its safety and effectiveness.

Internal Carotid Artery Tortuosity: Impact on Mechanical Thrombectomy

Background:

Although tortuosity of the internal carotid artery (ICA) can pose a significant challenge when performing mechanical thrombectomy, few studies have examined the impact of ICA tortuosity on mechanical thrombectomy outcomes.

Methods:

In a registry-based hospital cohort, consecutive patients with anterior circulation stroke in whom mechanical thrombectomy was attempted were divided into 2 groups: those with tortuosity in the extracranial or cavernous ICA (tortuous group) and those without (nontortuous group). The extracranial ICA tortuosity was defined as the presence of coiling or kinking. The cavernous ICA tortuosity was defined by the posterior deflection of the posterior genu or the shape resembling Simmons-type catheter. Outcomes included first pass effect (FPE; extended Thrombolysis in Cerebral Infarction score 2c/3 after first pass), favorable outcome (3-month modified Rankin Scale score of 0–2), and intracranial hemorrhage.

Results:

Of 370 patients, 124 were in the tortuous group (extracranial ICA tortuosity, 35; cavernous ICA tortuosity, 70; tortuosity at both sites, 19). The tortuous group showed a higher proportion of women and atrial fibrillation than the nontortuous group. FPE was less frequently achieved in the tortuous group than the nontortuous group (21% versus 39%; adjusted odds ratio, 0.45 [95% CI, 0.26–0.77]). ICA tortuosity was independently associated with the longer time from puncture to extended Thrombolysis in Cerebral Infarction ≥2b reperfusion (β=23.19 [95% CI, 13.44–32.94]). Favorable outcome was similar between groups (46% versus 48%; P=0.87). Frequencies of any intracranial hemorrhage (54% versus 42%; adjusted odds ratio, 1.61 [95% CI, 1.02–2.53]) and parenchymal hematoma (11% versus 6%; adjusted odds ratio, 2.41 [95% CI, 1.04–5.58]) were higher in the tortuous group. In the tortuous group, the FPE rate was similar in patients who underwent combined stent retriever and contact aspiration thrombectomy and in those who underwent either procedure alone (22% versus 19%; P=0.80). However, in the nontortuous group, the FPE rate was significantly higher in patients who underwent combined stent retriever and contact aspiration (52% versus 35%; P=0.02).

Conclusions:

ICA tortuosity was independently associated with reduced likelihood of FPE and increased risk of postmechanical thrombectomy intracranial hemorrhage.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02251665.

Predictors of First-Pass Effect in Endovascular Thrombectomy With Stent-Retriever Devices for Acute Large Vessel Occlusion Stroke

Background and Purpose

Successful recanalization after the first pass of the device in endovascular thrombectomy (EVT) can significantly improve patients' prognosis. We aimed to investigate the possible factors that influence achieving the first-pass effect (FPE).

Methods

We retrospectively analyzed the patients who underwent EVT caused by anterior circulation large vessel occlusion stroke (ALVOS) in our center. The FPE was defined as a successful recanalization [modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 defined as modified FPE (mFPE); mTICI 3 as true FPE (tFPE)] after one pass of the device without rescue therapy. Univariate and multivariate regression analyses were used to explore the predictors of FPE and the relationship between FPE and prognosis.

Results

There were 278 patients (age, 69.3 ± 10.9 years, male, 51.1%) included, 30.2% of them achieved mFPE, while 21.2% achieved tFPE. We found the higher clot burden score (CBS), the truncal-type occlusion, and the favorable anatomy of both extracranial and intracranial segments of the internal carotid artery (ICA) were associated with achieving mFPE. The higher CBS and truncal-type occlusion were statistically significant predictors of tFPE. Moreover, FPE was significantly associated with improved clinical outcomes, regardless of mFPE and tFPE.

Conclusions

The CBS, tortuosity of ICA, and angiographic occlusion type were independent predictors of achieving FPE. The rate of improved clinical and safety outcomes was higher in patients with FPE, which has important clinical significance.

Systematic Review on Endovascular Access to Intracranial Arteries for Mechanical Thrombectomy in Acute Ischemic Stroke

PURPOSE

In acute ischemic stroke for large vessel occlusions, delayed or failed access to intracranial occlusions has a negative impact on procedural and clinical outcomes. The aim of this review is to identify and quantify access failures and challenges in mechanical thrombectomy.

METHODS

A systematic literature review of PubMed and Scopus databases from January 2014 to October 2020 was performed. Articles reporting consecutive patients were used to calculate a crude failure rate of femoral and alternative accesses.

RESULTS

A total of 50 articles met the inclusion criteria, totalling 12,838 interventions. Failure to access the occlusion through transfemoral access occurred in 4.4% of patients, most commonly due to challenging supra-aortic vessel anatomy, decreasing to 3.6% when all alternative access routes were attempted. Failed access from alternative routes (direct carotid, radial and brachial approaches) attempted first-line or after failed femoral attempt were reported in 7.3% of patients. The occurrence rate of potentially challenging features (anatomical, diseases or others) ranged from 4.7% to 47.4%, primarily impacting the access time, procedure time, recanalization and clinical outcomes.

CONCLUSION

Failure to access the occlusion is a significant contributor to failed recanalization, regardless of access routes. Challenging, but eventually successful access is also a relevant factor in procedural and clinical outcomes; however challenging access requires a universal definition to enable quantification, so that methods for procedural optimization can be critically assessed.

Neovascularization and tissue regeneration by endothelial progenitor cells in ischemic stroke

Endothelial progenitor cells (EPCs) are immature endothelial cells (ECs) capable of proliferating and differentiating into mature ECs. These progenitor cells migrate from bone marrow (BM) after vascular injury to ischemic areas, where they participate in the repair of injured endothelium and new blood vessel formation. EPCs also secrete a series of protective cytokines and growth factors that support cell survival and tissue regeneration. Thus, EPCs provide novel and promising potential therapies to treat vascular disease, including ischemic stroke. However, EPCs are tightly regulated during the process of vascular repair and regeneration by numerous endogenous cytokines that are associated closely with the therapeutic efficacy of the progenitor cells. The regenerative capacity of EPCs also is affected by a range of exogenous factors and drugs as well as vascular risk factors. Understanding the functional properties of EPCs and the factors related to their regenerative capacity will facilitate better use of these progenitor cells in treating vascular disease. Here, we review the current knowledge of EPCs in cerebral neovascularization and tissue regeneration after cerebral ischemia and the factors associated with their regenerative function to better understand the underlying mechanisms and provide more effective strategies for the use of EPCs in treating ischemic stroke.